Distribution of R&D capacity in Africa.

Mapping of the top African cities by research output shows hotspots of R&D activity, but also highlights inequities in R&D productivity across the continent. To create this mapping we used articles with Africa-based authors in the corresponding address. A total of 20,119 articles were identified (Figure 2 and Text S1), but for simplicity only African cities with over 30 articles from 2004 to 2008 are marked. This represents 16,647 articles (circle diameter indicates number of published articles; a total of 91 cities in 28 countries are identified but only the top 40 are labeled).